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A. Find Color

time limit per test

2 secondsmemory limit per test

256 megabytesinput

standard inputoutput

standard outputNot so long ago as a result of combat operations the main Berland place of interest — the magic clock — was damaged. The cannon's balls made several holes in the clock, that's why the residents are concerned about the repair. The magic clock can be represented as an infinite Cartesian plane, where the origin corresponds to the clock center. The clock was painted two colors as is shown in the picture:

The picture shows only the central part of the clock. This coloring naturally extends to infinity.

The balls can be taken to be points on the plane. Your task is to find the color of the area, damaged by the given ball.

All the points located on the border of one of the areas have to be considered painted black.

Input

The first and single line contains two integers *x* and *y* — the coordinates of the hole made in the clock by the ball. Each of the numbers *x* and *y* has an absolute value that does not exceed 1000.

Output

Find the required color.

All the points between which and the origin of coordinates the distance is integral-value are painted black.

Examples

Input

-2 1

Output

white

Input

2 1

Output

black

Input

4 3

Output

black

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